Um, hmm. If you look at the overview picture it certainly looks like x8: http://www.jwele.com/motherboard_detail.php?419 http://www.ferra.ru/images/141/141084.gif because it's half the x16 slot. The J&W Manual does no specify and also the J&W website says 95W max but a J&W rep specifically told me 65W and with only 3 phase power for the CPU I personally wouldn't go over that. EDIT: The specification page on their website says 95W in well ventilated cases but they also said 4 phase could handle 125W CPUs then a lot of board makers decided against it earlier this year. It also says x4, but it's definitely electrically wider. I will have to look into it more, I only briefly checked the slot worked rather than seeing what Catalyst Control Centre said.